Behind the scenes of the fight over accessory dwelling units

February 19, 2025

By GINTAUTAS DUMCIUS

The MBTA Communities law, which requires Massachusetts cities and towns to zone for multifamily housing in areas close to public transit, sparked a battle over local versus state control. Some local officials chafed at the idea of state officials imposing zoning rules for their neighborhoods, and unsuccessfully went to court in a bid to weaken the law.

A similar but quieter fight, without the Supreme Judicial Court contretemps, played out earlier this year over accessory dwelling units, also known as ADUs, in-law apartments or “granny flats.” Used to house young and old relatives, and sometimes viewed as a less expensive alternative to senior housing, they’ve now become a key part of a state-level push to create more housing supply to meet intense demand.

On February 2, new state regulations went into effect allowing ADUs “by right,” meaning a special permit isn’t required for units under 900 square feet in districts zoned for single-family homes. Gov. Maura Healey’s housing office estimates that roughly 8,000 to 10,000 ADUs could be built over the next five years as a result.

The regulations are part of a law signed last year, the Affordable Homes Act, which seeks to encourage housing units to be built in order to add supply to low inventory, which is driving up the price of homes and rentals. The Healey administration wants to see 222,000 new units over the next decade. 

A number of communities had allowed accessory apartments through special permits, which added time to the development process. In some cases, the special permits limited them to owner-occupied single-family dwellings, or stipulated that only family members could use them.

But now, cities and towns can no longer require owner occupancy or a family relationship, and they cannot require a parking space for an ADU located a half mile from a bus station or other public transit stop. Municipalities can still impose rules around height and dimensions, under regulations issued by state housing officials.

In the leadup to the regulations taking effect earlier this month, some city and town officials, like the mayors of Malden and Fall River weighed in against allowing ADUs statewide “by right,” arguing there could be a stampede towards the construction of the units that could overwhelm their municipalities. CommonWealth Beacon obtained the comments through a public records request.

“This one-size-fits-all ADU law completely disregards local zoning regulations without considering the specific needs of individual cities and towns,” Fall River Mayor Paul Coogan wrote in his letter.

The comments offer a glimpse at the debate over housing that has played out community by community, with local officials and some neighbors objecting to more units and increased density close to their backyards, a stance that has contributed to the housing demand and supply crisis facing Massachusetts.

The Massachusetts Association of Realtors, which has 26,000 members, backed making ADUs “by right.” The association noted in its comments that the imbalance of housing and supply and demand is the result of “decades of abuse” of zoning powers, which have been used to exclude racial minorities, immigrants and lower-income people. The state must produce 20,000 to 25,000 new units of housing a year in the next five years to stabilize pricing, and the law and regulations are a “real step” towards that goal, the association wrote.

The Massachusetts branch of AARP also voiced support, calling them “one of the best ways for older family members to age in place,” as well as “create multi-generational housing opportunities,” and become a source of income for older residents who rent theirs out.

The comments in support of the law and the regulations also point to a more concerted effort among housing advocates to push back against the opposition. In the last several years, pro-housing groups have sprung up, particularly in eastern Massachusetts, where advocates are appearing at local meetings to voice support for individual development projects that bring more housing.

“I think ADUs are a really gentle form of development,” said Jesse Kanson-Benanav, executive director of Abundant Housing Massachusetts in an interview. “We’re talking about small units, either in people’s backyards or a new addition to their house.”

Abundant Housing was among the groups that sent in comments backing the concept of ADUs “by right” across the state. “I don’t expect there’s going to be huge, huge groundswell in ADUs, at least in the immediate term,” Kanson-Benanav said. If the state is hitting its projected target of 8,000 to 10,000 over five years, that may amount to “a couple of ADUs per year, per community,” he said.

But others sought to retain some local control over ADUs. State Sen. Patrick O’Connor, who represents several South Shore communities, including Weymouth, Hingham, Duxbury, Scituate and Cohasset, called the process to allow ADUs “rushed” and said it could lead to unintended consequences.

There is growing worry among municipal officials and real estate professionals that corporations will buy up housing stock, “hastily” build ADUs, and then rent the units out, he said. In his public comment on the regulations, he argued for allowing a requirement that property owners occupy either the primary residence or the ADU on any property that applies to build an ADU. 

Kanson-Benanav called such a suggestion, which was not included in the final regulations, a “roundabout way to block” ADUs. Most banks will not help finance the construction of ADUs with that type of owner-occupancy restriction, he said.

O’Connor reiterated his concern that some areas could become dominated by rentals owned by investors as a result of the regulations. “This change introduces uncertainty around the potential for school district overcrowding, limitations on parking, and increased public safety demands, all while reducing home ownership opportunities for families,” he wrote in an email.

In the city of Fall River, which has 94,000 residents and is next to the border Massachusetts shares with Rhode Island, Coogan said ADUs can help with the housing shortage. But he would prefer the state focus on pushing rules and requirements on cities and towns that haven’t built much affordable housing, rather than cities like his.

He would prefer to retain local control, and he said his zoning board routinely approves in-law apartments. But ADUs “can get out of hand very quickly as people try to convert a garage or a basement,” he said. “I’m just concerned about it.”

He added that the city will follow the state law. “We’ll work our way through it and go on to the next thing, he said.